Many people mistakenly believe synthetic cannabinoids closely mimic the effects of marijuana, but there are significant differences. Although research is limited, preliminary studies suggest that effects include:

• Feeling stimulated and energetic
• Increased appetite
• Producing a dream-like state
• Nausea and vomiting
• Seizures
• Aggression and agitation
• Respiratory failure
• Loss of consciousness

In 2015, poison control centers received just under 10,000 calls reporting adverse reactions to synthetic cannabinoids, and emergency rooms received tens of thousands of patients. These numbers have since gone down.

One explanation for the high number of hospital visits is that other substances in marijuana known to protect against anxiety and psychotic symptoms likely balance out the direct effects of THC on the brain. These substances are absent in synthetic cannabinoids.

Until more research is done on individual synthetic cannabinoids, specific causes for these effects will remain only partially understood.